[Perndog]

I think if the offender's income is below a certain amount (read: the offender is completely destitute) the sentence should be regular community service until the offender raises his income to the baseline and a fine to be paid at that point.

That's the most realistic thing I can think of. Ideally, I'd prefer that anyone too poor to support himself who is also a criminal (and I don't consider drug users or dealers criminals in this ideal country) should be publicly executed or deported (whether or not he was born in the USA).